[vtkusers] vtkCamera focal length to pixels

[David Gobbi]

By pixels, you mean screen pixels?  The camera's vertical field of view,
in pixels, is equal to the height of the viewport, which you can get by
calling GetSize() on the renderer.  The vertical field of view, in mm, is
controlled by setting the ViewAngle and Distance of the camera.  The
distance, field of view, and view angle are related by a simple equation
involving the arctan of half the view angle.  Draw a diagram and you
should be able to derive the equation without much trouble ;)

 - David


On Fri, Sep 19, 2014 at 5:56 AM, luta <sharmaatul11 at gmail.com> wrote:
> Hi there, I am trying to convert vtkcamera focal length (mm) into pixels so
> that I can use this to create an intrinsic matrix of the vtkcamera. It would
> be a great help is someone would guide me in converting vtkcamera focal
> length into pixels.